Typically adderall is out of your system fairly rapidly, which is why you have to take it every day. The fatigue you are feeling could well be because it is essentially speed and jacks you up, with out it you don't have the energy. However, its not supposed to work that way with ADHD - so if that was your diagnosis and the reason for taking it, you might want to question that diagnosis.
You may well have trouble sleeping due to your asthma medicine. Many of them are uppers and can cause sleep problems - all depends on what you are taking. The inhalers are banned before most athletic performances for this reason.
I agree with allmymarbles, Xanax can be troublesome and typically is stopped after about 4 months. By the way, if you ever decide to cut it down, due it only under doctor supervision. IT CANNOT BE STOPPED SUDDENLY.
I think you need someone to take a look at all of the medications you are taking and their effects on eachother. Once again, the asthma medication may be part of the problem depending on its ingredients.
Let us know what you find out.
Also, take a look at your ambian as to stomach pain or upset. I was on it for about 5 months and my stomach got so bad I couldn't eat without pain. I quit taking it 3 weeks ago and it's like magic, no pain!
I too took Adderall for 18 months and quit all at once. Now I take on an as need basis. I'm finding I do ok without it and I can sleep again at night without the ambian. Oh and my blood pressure is back to normal as well.
Are you aware that Xanax is highly addictive? Also, your dosage is very large. Xanax is best used on an as-needed basis to avoid addiction. You might want to speak to your pharmacist about this medication. He will have more information than your doctor because he is someone who has studied medications for four years.